http://www.youtube.com/watch?v=jnrrHfSYoi4
Holy shit, and it totally surprised me. He is buds with Yelawolf, so I assume Yela gave him some tips and taught him how to rap. Margera's flow is nearly identical to that of Eminem in "Hellbound", and even the lyrics are pretty decent and relatable to the average joe. The beat is fucking monstrous too. This song is an awesome hip-hop / rock hybrid pretty similar to Yela's style.
If this gets some air play (maybe releasing a clean version of it), I can see this becoming a huge hit. Guys, don't sleep on him.